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The present invention relates to a vehicular lamp provided with a plurality of LED light sources, and more particularly to a vehicular lamp in which light is radiated using an indirect illumination technique.
Recently, vehicular lamps provided with an LED light source have frequently been employed. As described in Japanese Patent Application Laid-Open No. 11-306810, a lamp has been developed which provides a soft lighting effect using an indirect illumination technique whereby the LED light source is arranged so as not to be visible from the front of the lamp. Also, there has been known an indirect illumination type vehicular lamp structure in which a Fresnel lens is provided together with an LED light source, as described in German Patent Application No. 19638081.
FIGS. 9 and 10 are respectively a front elevational view and a side cross-sectional view showing a vehicular lamp 100 of this type.
As shown in these drawings, in the vehicular lamp 100 light from a plurality of upward directed LED light sources 102 is formed into upward directed parallel light fluxes by a plurality of Fresnel lenses 104 provided near the upper side of the light sources 102. The parallel light fluxes from the respective Fresnel lenses 104 are reflected toward the front of the lamp by a reflector 106.
It is possible to effectively utilize the light source light by combining the LED light sources 102 and the Fresnel lenses 104 in this manner. However, in the conventional vehicular lamp 100, there is a room for improvement in appearance when the lamp is lit.
That is, the reflecting surface 106a of the reflector 106 of the vehicular lamp 100 is divided into a plurality of segments with respect to the vertical direction, providing it with a stepped shape. Each segment is composed of a reflective element 106s reflecting a portion of the parallel light flux from the respective Fresnel lenses 104 in a diffused manner toward the front of the lamp and a step portion 106r extending in the vertical direction.
When viewing the reflecting surface 106a of the reflector 106 from directly in front of the lamp when the lamp is lit, a portion of each of the reflective elements 106s appear bright. However, the step portions 106r, which the parallel light fluxes from the Fresnel lenses 104 do not strike, appear dark, making the overall appearance of the lamp uneven, and hence not satisfactory.
Taking the foregoing situation into consideration, it is an object of the present invention to provide a vehicular lamp of a type in which light is radiated by indirect illumination using a plurality of LED light sources and which has an improved appearance when the lamp is lit.
The present invention achieves the above and other objects by providing a vehicular lamp of the above-mentioned type having an improved reflector structure.
More specifically, a vehicular lamp according to the present invention is provided with a plurality of LED light sources, a plurality of lenses for forming parallel light fluxes from respective ones of the LED light sources, a reflector for reflecting the parallel light fluxes from respective ones of the lenses toward the front of the lamp, and a translucent cover provided on the front side of the reflector, wherein the plurality of LED light sources are divided into a first LED light source group and a second LED light source group, the plurality of lenses are divided into a first lens group which forms light from the first LED light source group into parallel light fluxes radiating in substantially the same first direction and a second lens group which forms light from the second LED light source group into parallel light fluxes radiating in substantially the same second direction with the first and second directions intersecting at a predetermined angle in a front view of the lamp, the reflecting surface of the reflector is divided into a plurality of segments, and a first reflective element for reflecting the parallel light fluxes from the first lens group and a second reflective element for reflecting the parallel light fluxes from the second lens group are formed in each of the segments.
The specific structure of the lenses is not particularly limited as far as the lenses can form the light from each of the LED light sources into a parallel light flux. For example, it is possible to employ a single spherical lens, a combination lens, a Fresnel lens or the like.
Concerning the direction of the parallel light fluxes mentioned above, the specific direction thereof is not particularly limited as far as the direction is along a line intersecting the longitudinal direction of the lamp; for example, it is possible for the direction of the parallel light fluxes to be an upward direction or a lateral direction by making such direction orthogonal to the longitudinal direction of the lamp.
The term xe2x80x9cintersect at a predetermined angle in a front view of the lampxe2x80x9d means not being arranged parallel to the front view of the lamp. Also, the intersecting angle is not particularly limited.
Structural details, such as shape, size and the like, of each of the first and second reflective elements is not particularly limited as far as these elements are structured so as to reflect the parallel light fluxes from each of the lenses toward the front of the lamp. Moreover, the arrangement of the segments is not particularly limited.
As discussed above, the vehicular lamp according to the present invention is structured so as to form the light from a plurality of LED light sources into parallel light fluxes with a plurality of lenses and reflect the parallel light fluxes toward the front of the lamp with the reflector. The radiating direction of the parallel light fluxes from the first lens group and the radiating direction of the parallel light fluxes from the second lens group are set so as to intersect at a predetermined angle in the front view of the lamp. Further, the reflecting surface of the reflector is divided into a plurality of segments, and the first reflective element for reflecting the parallel light fluxes from the first lens group and the second reflective element for reflecting the parallel light fluxes from the second lens group are provided in each of the segments. With this structure, the following effects can be obtained.
That is, each of the segments appears bright in the area of the first reflective element and the portion of the second reflective element when viewing the reflecting surface of the reflector from the directly in front of the lamp when the lamp is lit. Therefore, it is possible to make the reflecting surface visible over a wide viewing range compared to the conventional reflector.
Therefore, according to the vehicular lamp of the present invention where light is radiated by indirect illumination using a plurality of LED light sources, the appearance of the lamp when the lamp is lit is improved.
In the inventive lamp, the arrangement of the first reflective element and the second reflective element in each of the segments is not particularly limited, as mentioned above. However, in the case where a first reflective element and a step portion are provided for the parallel light fluxes from the first lens group and the second reflective element is provided for the parallel light fluxes from the second lens group, it is possible to make a part of the step portion which corresponds to a dark portion in the conventional lamp appear bright due to the presence of the second reflective element, thereby achieving a better overall appearance of the lamp.
Further, in the case where the radiating direction of the parallel light fluxes from the first lens group is in an upward direction and the radiating direction of the parallel light fluxes from the second lens group is in a lateral direction of the lamp, it is readily possible to provide mounting space for the first LED light source group and the first lens group and mounting space for the second LED light source group and the second lens group, and it is also possible to maximize the reflection efficiency of each of the first reflective elements and each of the second reflective elements by making the radiating direction of the parallel light fluxes from the first lens group and the radiating direction of the parallel light fluxes from the second lens group orthogonal in the manner mentioned above.
Moreover, in the case where the first reflective elements and the second reflective elements are each constituted by a curved surface which reflects the parallel light fluxes from the lens in a diffused manner in vertical and horizontal directions, it is possible to obtain the required lamp light distribution performance even if the translucent cover is plain. (By xe2x80x9cplainxe2x80x9d is meant that the cover contains no lens elements or the like to diffuse the light passing therethrough.)
In an alternative embodiment, each of the first reflective elements and each of the second reflective elements may be constituted by a flat surface so as to reflect the parallel light fluxes from the lens toward the front of the lamp while maintaining the light fluxes in a parallel state, in which case diffusion lens elements are formed in the translucent cover or the like to diffuse the light in the vertical and lateral directions. In another alternative embodiment, one of the first reflective elements and the second reflective elements are constituted by curved surfaces having curvature only in one direction so as to reflect the parallel light fluxes from the lens toward the front of the lamp only in one direction in a diffused manner, and which case diffusion lens elements are formed in the translucent cover or the like to diffuse the light passing through the cover in the direction orthogonal to the one direction.
The application of the vehicular lamp of the invention is not particularly limited. However, if embodied as a tail and stop lamp, with the first LED light source group used in a tail lamp lighting mode and the first LED light source group and the second LED light source group in a stop lamp lighting mode, it is possible to make the appearance of the lamp different between the two lighting modes, lending novelty to the appearance of the lamp when lit.